On Sat, 6 Jul 2019 at 15:13, steve-ALUG@hst.me.uk wrote:
I don't understand the underlying reason why you're trying to do what you're trying to do. What's the top-level reason for wanting to do this
- i.e. what's your initial purpose?
OK, fair question; I have explained some of it above but I'll go into more depth.
I do quite a lot of work on Raspberry Pi's. I back them up periodically as a tarball of the whole filesystem because it's the entire system I'm interested in, not just one or two files.
The result is dozens of tarballs and no easy way to get a simple view of what has changed between them. Changes fall into several categories: - Mundane updates (apt upgrade etc) - lots of files change but nothing of substance - Package installs (apt install xxx) - lots of files get added but can be summarised by the list of packages installed - Configuration file changes - Additions/Changes to my own scripts
Since what I am working with are tarballs, the easiest starting point is the file list; it's trivial to extract the file listing from a tarball and make comparisons between two of them, but when thousands of files can be changed with only a handful of actual changes this is really an exercise in seeing the woods for the trees.
Or consider this example: - I have a Pi SD card based on Raspbian Jessie and several months of tweaks and updates (including package additions and removals) - I want to summarise the changes I've made to I can re-run them on a clean install (or on Raspbian Buster), using the file listings from a clean install and my working copy as the starting point
Hope that's clearer. Bottom line: What I have is dozens of full OS tarballs that I need to compare, and "installed packages X, Y & Z" is far more useful to me than "added <list of hundreds of new files>".